Crane system for cargo containers

ABSTRACT

A container head, supported by cables via a spreader bar, is provided with locking devices at the four corners for engaging a cargo container. When the container head is in place on a container, the container can be engaged or disengaged with respect thereto, but the locking devices cannot be operated when the container head is not in place, e.g., when the container head is performing a lifting function. Guides, located at the sides and ends of the container head, as well as tag motors for &#39;&#39;&#39;&#39;reining&#39;&#39;&#39;&#39; the container head, assist a crane operator in positioning the head on a container.

United States Patent 1 Wilson et a1.

[ 1 CRANE SYSTEM FOR CARGO CONTAINERS [75] Inventors: Lester W. Wilson,Portland; Joseph H. Tracy, Troutdale', Clarence C. Wilson, Portland, allof Greg.

[73] Assignees: Lester W. Wilson; Clarence C.

Wilson, both of Portland, Oreg.

[22] Filed: Apr. 20, 1973 [21] Appl. No.: 352,876

Wyrough 294/67 DA 3,378,158 4/1968 Lopez 254/172 3,501,193 3/1970 Gray294/67 R 3,520,431 7/1970 Tax 294/67 R Primary ExaminerEvon C. BlunkAssistant Examiner-Jeffrey V. Nase Attorney, Agent, or Firm-Klarquist,Sparkman, Campbell, Leigh, Hall & Whinston [57] ABSTRACT A containerhead, supported by cables via a spreader bar, is provided with lockingdevices at the four corners for engaging a cargo container. When thecontainer head is in place on a container, the container can be engagedor disengaged with respect thereto, but the locking devices cannot beoperated when the container head is not in place, e.g., when thecontainer head is performing a lifting function. Guides, located at thesides and ends of the container head, as well as tag motors for reining"the container head, assist a crane operator in positioning the head on acontainer.

11 Claims, 11 Drawing Figures PATENTEU 3 885 676 SHEET 2 FIG. 3 f

SHEET FIG. ID

THE

AIR SUPPLY FIG. 8

IZZdK 1 22b I D m I c w w m Gr V ZVM 1\ D 0 m 9 C o L N u a 2 2 CRANESYSTEM FOR CARGO CONTAINERS BACKGROUND OF THE INVENTION This inventionrelates to a crane system for cargo containers and particularly to asystem which facilitates rapid loading and unloading of the containersin a safe manner.

Cargo containers have recently become popular for facilitating the rapidloading and unloading of ship car goes to or from trailer-trucks andrailroad cars. For example, a cargo container may be transported on atruck body to dockside where the same may be hoisted as a unit into thehold of an awaiting ship. However, some difficulty is experienced inaccurately guiding these rel atively massive loads from a crane. inmoving the same into position. Also. container heads," heretoforeemployed for engaging the containers, have themselves been heavy instructure for enabling these heads to carry the weight of a container.Furthermore, the loading or unloading of cargo is difficult anddangerous when the crane operator cannot actually see when the containeris being engaged or disengaged, even though manual assistance may beprovided. A particularly dangerous situation arises when it is believeda container is fully down and positioned inside a ships hold, when, as amatter of fact. one or more corners of the container are not fullysupported from underneath. When the container head is then remotelyunlocked for releasing the container, the heavy container may beinadvertently dropped some undetermined distance, or may even tip to oneside, resulting in costly damage and extreme danger to personnel. Thesefactors tend to decrease the speed with which the loading or unloadingoperation might otherwise be performed.

SUMMARY OF THE INVENTION According to the present invention, a cranesystem for cargo containers includes a container head adapted to bereceived upon the top of a container, the container head being providedwith a plurality of remotely operated locking members for engaging aplurality of matching locking devices provided at the top of thecontainer. Cable means suspend the container head from a crane boom, andmeans are responsive to the tension in said cable means for preventingunlocking of the said locking members in the presence of tension in thecable means.

In a preferred embodiment, the means responsive to tension in the cablemeans for preventing unlocking of the locking members includes pluralpressure-sensitive switching devices operative, when the weight of thecontainer head is not resting on the container. for inhibiting unlockingoperations of the locking members.

According to an embodiment of the present invention, the cable meansincludes a spreader bar posi tioned between the crane boom and thecontainer head for more adequately supporting the container head andcontainer at the corners thereof to reduce the size and weight of thecontainer head structural members.

The system according to the present invention also desirably includes aplurality of hingeable guides located on the container head and adaptedto be rotated into a position extending downwardly from the containerhead. These guides are supported in their down ward position withbracing means for taking the thrust of lateral forces when the guidesencounter the side of a container.

According to the preferred embodiment of the present invention, thecrane system includes tag motors for operating tag lines viaair-operated clutches for guiding or reining' a container head andcontainer into a de' sired position or orientation.

It is accordingly an ()hJCCl of the present invention to provide animproved crane system for cargo containers which expedites the handlingof such containers while maintaining safety with respect to property andpersonnel.

It is a further object of the present invention to provide an improvedcrane system for cargo containers wherein the crane system operator isin maximum con trol of container movement despite visual difficultiesencountered when the container is in a ships hold or the like.

It is another object of the present invention to provide an improvedcrane system for cargo containers enabling use of a container head ofcomparatively light construction.

It is another object of the present invention to provide a crane systemfor cargo containers which is safe in its operation.

It is another object of the present invention to provide a crane systemfor cargo containers facilitating the rapid and safe movement of acontainer head onto and away from a container.

The subject matter which we regard as our invention is particularlypointed out and distinctly claimed in the concluding portion of thisspecification. The invention, however, both as to organization andmethod of operation, together with further advantages and objectsthereof, may best be understood by reference to the followingdescription taken in connection with the ac companying drawings whereinlike reference characters refer to like elements.

DRAWINGS FIG. 1 is a side view of a crane system according to thepresent invention;

FIG. 2 is an elevational view of a spreader bar according to the presentinvention, said view being taken at 2-2 in FIG. 1;

FIG. 2A is a cross section of the FIG. 2 spreader bar taken at 2A2A inFIG. 2;

FIG. 3 is a top view, partially broken away, of a por tion of the cranesystem according to the present invention including tag motors and amounting platform therefor, FIG. 3 being taken at 3-3 in FIG. 1'.

FIG. 4 is a top view, partially broken away, of a container headaccording to the present invention, FIG. 4 being taken at 4-4 in FIG. 1;

FIG. 5 is a side elevational view, partially broken away, of the FIG. 4container head;

FIG. 6 is a partially broken away cross-sectional detail of a lockingdevice positioned at a corner of the FIG. 4 container head and includinga switching device 106 according to the present invention. FIG. 6 beingtaken at 6-6 in FIG. 4',

FIG. 7 is a partially broken away cross-sectional view of a hingeableguide employed according to the present invention, this view being takenat 7-7 in FIG. 4;

FIG. 8 is a schematic diagram of electrical control circuitry accordingto the present invention.

FIG. 9 is a diagram of a hydraulic system according to the presentinvention; and

FIG. is a diagram of a pneumatic system according to the presentinvention.

DETAILED DESCRIPTION Referring to the drawings and particularly to FIG.I, a container cargo system according to the present invention includesa conventional crane 10 including a boom 12 supporting cable means 14carrying blocks 16. The crane is conventionally a two-drum crane havinga pair of cable systems in side-by-side relation for simultaneouslylifting both ends of a load, only one cable system being illustrated inthe side view of FIG. 1. The hooks 18 of blocks 16 support a spreaderbar 20 more fully illustrated in FIGS. 2 and 2A, the spreader barcomprising a central pipe member 22 having a pair of upper ears 24supported from hooks 18 via intervening shackle members 26. Lower ears28 welded to pipe member 22 are provided with side plates 30 disposed inspaced relation on either side of cars 28 for supporting sheaves 32 overwhich side cables 34 extend, there being four pairs of such side cablesattached in supporting relation to four corners of container head 36 inFIG. 1. The spreader bar 20 is actually proportionately much longer thanis depicted for the sake of convenience in FIG. 2, and in a particularinstance is approximately 7 feet long. The spreader bar 20, placedintermediate cables 14 and 34, maintains a nearly in-line conditionbetween the same, or an angle of nearly 180, while spreading the cablesfor optimum support of container head 36. By means of this arrangement.the container head is adequately supported at the corners thereof, atwhich points the container itself is supported, whereby the structuralconstruction of the container head need not be as heavy or cumbersome asin the case of prior container heads. Container head 36 supports anelectrical cable holder 38 receiving electrical cable 40 in coiledrelation therewithin. Cable 40, which provides for remote operation ofcontainer head functions, is ultimately connected to the cab of thecrane by means not shown.

The crane 10 is further provided with a forward platform 42 asillustrated in FIG. 3 upon which tag motors 44 are located. These tagmotors include electrical drive motors 46 and a pneumatically operatedclutch 48 through which chain drive 50 rotates cable reels 52 aboutwhich tag cables 54 are wrapped. The tag cables 54 respectively passover sheaves 56 mounted on either end of a tag cable bar 58, and fromthence the tag cables pass down to spaced locations on the front sidecontainer head 36 where the same are attached. Only one cable 54 isshown in FIG. 5, illustrating the container head, since the view isbroken away, but the remaining cable 54 is suitably connected to thecontainer head at a location symmetrically spaced at the opposite sideof the container heads center line. The crane operator is provided withan air valve 60 for operating each tag motor clutch, such air valvebeing coupled to an air supply 62 as illustrated in FIG. 10. By means ofoperation of a pair of valves 60, the clutches 48 may be individuallyoperated while motors 46 continuously run whereby to control the tensionin cables 54. It will be seen that differential pressure on clutches 48can be used for "reining" the cables 54 whereby to guide and angularlyposition the container head 36. Accordingly, the tag motors are not onlyuseful in guiding the container head to and from a container, but arealso useful in guiding and positioning a container when supported by thecontainer head.

In the particular instance illustrated in FIG. I, the container head 36is positioned on top of a container disposed on a truck trailer 72 whichsupplies a sup porting surface for the container 70. The hold of a shipor the deck of a pier can also supply a supporting surface. Thecontainer head system may be employed for lifting the container 70 fromthe truck trailer and placing the same in the hold of a cargo ship, orvice versa, but in either case the present system provides the desiredcontrol and positioning required for these maneuvers.

The container head 36 further includes hingeable guides 74 which may berotated downwardly into the position illustrated in FIG. 1 to guide thecontainer head 36 onto container 70. In the illustrated view, two of theguides shown are lowered and one, numbered 74', is illustrated inupraised position, which is the typical manner in which the guides willbe employed in approaching the container 70 from the left and from theposition of the viewer in FIG. 1. In addition, a further side guide willbe in lowered position on the left-hand side of container 70, while tworight-hand guides and a guide at the rear of the container 70 will be inupraised position. When the container head 36 is finally disposed inproper position on a container 70, locking members as hereinafter morefully described are operated to engage locking sockets provided in thecontainer at the four corners thereof.

Referring now to FIGS. 4 and 5 illustrating the container head 36 ingreater detail, the container head comprises side beams 76, and endbeams 78 joined thereto, for completing a rectangular configurationgenerally matching the top dimensions of the standard cargo container.The container head is provided with various side bracing members 80 andis also provided with a locking device 82 disposed at each cornerthereof for engaging the container. As illustrated, the cables areattached to gusset members 84 secured to the corners of the structureproximate the location of locking devices 82. The container head is alsoprovided with indicating means 86', 88' and 90' comprising indicatinglamps as hereinafter more fully described, and the container head alsosupplies support for hydraulic cylinders as hereinafter more fullydescribed as well as a reservoir of hydraulic fluid, pumping means,valving means, and the like by means of which the hydraulic cylindersare controlled.

Referring now to FIG. 6 illustrating a locking device 82 in greaterdetail, the said device is enclosed in a box structure 92 at a corner ofthe container head 36 which includes a sleeve 68 journaling a lockingshaft 94 at the lower end of which is a locking male member 96 adaptedto engage a slot in a female receptacle or socket 98 located at a cornerof the container 70. Both the slot and member 96 are elongated such thatthe member 96 may enter the slot and then be rotated by 90 for engagingthe underside of the receptacle for supporting the container 70. Theshaft 94 is rotated by actuating rod 100 ofhydraulic cylinder 102 theremaining end of which is pivotally attached to plate welded to a sidebeam 78 of the container head 36. The actuating rod 100 is pivotallyconnected to a crank 104 which is unitary with a supporting collar 66secured to shaft 94 whereby extension of actuating rod 100 rotateslocking member 96 into the locking position as is illustrated in thedrawing. Stop 64, also secured to collar 66, limits rotation of thelocking member to its correct locking position when stop 64 strikesgusset 84.

The container head is provided with tension detecting means at the fourcorners thereof for ascertaining when the cable system comprising cables34 is under tension, and when the same is slack indicating the containeris no longer being lifted or supported by the cables. In the illustratedembodiment, the tension detecting means comprises a pressure sensitiveswitching device 106 disposed at the underside of each corner ofcontainer head 36. This switching device comprises a plate 108 which isprovided with a pivotal connection 110 for pivotally supporting the samefrom an underplate 112 secured at the bottom of box structure 92 of thecontainer head structure. The plate 98 also includes an invertedL-shaped upward extension 114 apertured to receive a threaded switchactuating rod 116 of a switch 118 secured to a wall of box structure 92.The rod 116 extends through the aperture in the upper leg of theL-shaped extension 114 and is provided with adjusting nuts such thathingeable movement of plate 108 operates the switch. The remote end ofL-shaped extension 114 is attached by a spring 120 to the upper part ofbeam 78 whereby the plate 108 is normally biased in a downward positionindicated by dashed lines in the drawing. At this time switch 118,provided with normally open contacts, affords no electrical connectionin the circuit in which it is disposed. However, when the container headis located on the container as illustrated in FIG. 6, plate 108 pivotscounterclockwise to the position shown in full line in FIG. 6 againstthe bias of spring 120, and the normally open contacts of switch 118become closed.

As hereinafter more fully described, a locking device 82 may be operatedonly when closing of the contacts of switch 118 indicates the containerhead is resting on container 70. If the container head has neitherengaged a container at all, or if the container head is lifting acontainer such that the top of member 96 engages the underside of thetop of socket 98, then the switch plate 108 will be in its clockwiseposition, opening contacts 118. Thus, closing of the contacts of switch118 indicates a slackness in the cables 34 lifting the container head.FIG. 6 shows the relative position of the different parts when the sling34 is fully slack, and the crane is not supplying any lift. Under theseconditions, provided the container head is properly seated on thecontainer sockets 98, the underplates 112 of the container head rest onplates 108, which rest on the tops of sockets 98. Under this condition,and only under this condition, are the switches 118 closed. When thesling 34 is tensioned, the container head lifts slightly till lockingmale members 96 engage the under-abutting surfaces of sockets 98. Thesmall upward movement of the container head permits underplates 108 tomove towards the dotted position shown in FIG. 6, thereby openingswitches 118. Thus, switches 118 are closed only when the container headis fully down on the sockets 98 of the container, and, when hoistingbegins, the initial tensioning of the sling 34 immediately opens theswitches 118, even before the crane takes enough strain to lift thecontainer 70 off its supporting surface, such as truck trailer 72. Ashereinafter more fully described, contacts of switches 118 disposed atthe four corners of the container head are connected in series, and allfour sets of contacts must be closed in order to operate the lockingdevice 82 either from a locked to an un' locked position, or from anunlocked to a locked position. Hydraulic cylinder 102 is also providedwith a switching device 122 conveniently mounted on a gusset member 84,the switching device being operated by a collar 123 on actuating rod toindicate when the actuating rod 100 is extended. When the actuating rodscorresponding to all switches 122 are extended, i.e., when the lockingmembers 96 at all four corners engage the sockets 98 of a container inlocking relation, an indiction is given to the operator.

FIG. 7 illustrates a guide 74 in greater detail. Guide 74 comprises aguide arm or first arm 124 which is pivotally engaged at 126 to theupper part of a hook struc ture 128 joined to one of the beams, i.e.,beam 78, forming a part of a main structure of the container head. Theup" position for the guide is shown in full line, and the down" positionin dashed line. The guide arm 124 has nearly the shape of a \V"including a straight portion 130 adapted to engage the side of container70 when the arm is in lowered position, and a bent-out portion 131extending therebelow. Above the location of the side of the container,the guide arm 124 includes a section 132 extending back to a pivot pin134 adapted to be downwardly received in the up wardly facing opening136 of hook structure 128. The remainder of arm 124 extends to pivot126.

A second arm 138 is connected to arm 124 by pivot pin 134 and arm 138 isin turn pivotally connected to a third upwardly extended arm 140 havingthe shape of an inverted V when arm 124 is in its downward or dashedline position. The remaining end of third arm 140 is pivotally joined toa plate 142 secured to the structure of container head 36. The apex ofthe V is pivotally joined to the actuating rod 144 of a hydrauliccylinder 146, the remaining end of which is connected to a plate 148 bymeans of a pin 150. The plate 148 is welded to the container head,

When not in use, the guide 74 is maintained with guide arm 124 in theupraised position. When it is desired to lower the same, cylinder 146 isactuated to move rod 144 outwardly in a direction to the left in FIG. 7which in turn rotates third arm 140, second arm 138 and first arm 124 ina counterclockwise direction. The pivot pin 134 is received within theopening 136 of hook structure 128, the pivot pin 134 moving downwardlyinto the opening by means of the linkage provided. When it is desired tomove the first arm 124 to its original position, the hydraulic cylinder146 is operated in its reverse direction for easily moving the arm 124upwardly. However, it will be realized that during the course of movingthe container head relative to a container while maintaining a group ofarms 124 in their downward position, the arms 124 will encounter thecontainer by striking the same. According to the illustrated device, theforce upon the arm 24 will be sideways, i.e., to the left in FIG. 7against the downwardly extended arm 124. The force is received by thelefthand side of the hook opening 136 by the hook structure 128 toprevent damage to the linkage and to the cylinder 146 as would preventoperation of the device.

Normally, the guides 74 are used by threes. That is, the arms on oneside and one end of the container head will be lowered, while the armson the remaining side and end will be upraised, while the container headis moved towards the container until the side and end with the loweredarms encounter the container whereby the container head can be guidedonto the container. As the container head is correctly positioned. thesame 1\ moved downwardly \vlicrcbv the locking members 96 becomeinserted in sockets )8. Then the locking devices 82 are operated,assuming pressure sensitive switching devices 106 all indicate thecontainer head is firmly in place The container 111d then be lifted bymeans of the container head and crane to the desired location. Thelocking devices 82 may not be unlocked until the container is relocatedon the lirin ba e and the sv itching devices 106 again indicateslackness in the cables as the container head rests upon the containerTherefore the cylinders 102 may be op eratcd For unlocking the devices82 at this time, after which the container head may be safely upraised.

FIGS. 8 and 9 will now he considered, these figures respectivelyillustrating electrical and hydraulic diagrams according to the presentinvention. The electrical control diagram of FIG. 8 includes connections152 and 154 to a source of control voltage. The switches 118 at the fourcorners of the container head are connected in series as indicated at118a, 118b, 1180, and 118d, such series circuit being connected betweenline 154 and operator's lamp 86 in the cab of the crane, which indicateswhen the four corners of the container are down, i.e., lines 34 areslack. In addition, an amber lamp 86 in parallel with lamp 86 andlocated on the container head is illuminated at this time for indicatingto workers in the vicinity when the corners are fully down. Lamps 86 and86' are returned to line 152. Further in parallel with the lamps 86 and86 are relay operating coils R1 and R2 which operate contacts R1 and R2,respectively in series with lock and unlock solenoids 156 and 158. Locksolenoid 156 is disposed between line 152, and the series connection ofcontacts R1 and the normally open contacts of a double throw switch 160returned to the remaining line 154. Unlock solenoid 158 is disposedbetween line 152, and the series connection of contacts R2 and thenormally closed contacts of switch 160, returned to line 154. Switch 160is a lock-unlock control switch located in the operator's cab of thecrane. Solenoids 156 and 158 operate valve 162 in FIG. 9 between lockand unlock positions for operating the hydraulic cylinders 102 betweenlock and unlock positions. Hydraulic fluid is delivered via lines 163and 166 for operating cylinders 102 for respectively locking andunlocking the devices 82. Hydraulic fluid is pumped by pump P fromreservoir R to the valve, and hydraulic fluid is returned from the valveto the reservoir. The hydraulic system elements are all suitably mountedon the container head and remotely operated electrically as describedherein. When the crane lowers the container head fully upon a container,all of the switches 118a, 118b, 118C. and 1184 should close. and lamps86 and 86' will light. At this time. contacts R1 and R2 will closepermitting the operator to operate lock solenoid 156 by throwing switch160 to the left. However, if all the corners are not down. the seriescircuit through switches 118a, 118/1, 118e, and 118d will be broken,control coil R1 will fail to operate contacts R1, and consequently thecorners of the container head cannot be changed from an unlocked to alocked condition. Assuming, however, that the corners of the containerhead are locked in place, it will be seen that the same cannot beunlocked until the lines are slack as detected once again by clo sure ofswitches 118a, 118b, 118e, and 118d Thus,

Ltitttttcts R2 t lll remain open and despite the operators throwincwitch 160 from the left hand position to the right It ind position. thecontainer head will remain locked to the container. This preventsunloading the container or dropping a part of the container when some orall of the corners of the container are not in place and the actualposition of the container may not lie observable by the crane operator.

The switches associated with the respective locking cylinders 102 areindicated at 122a, 122b, 122C, and 1221! in FIG 8. The switches aredisposed in series between line 154 and the parallel combination oflamps and 90' returned to line 152. The lamp 90 is in the operators cab,and lamp 90' is disposed on the con tamer head. Thus, the operator aswell as other workers in the vicinity can be assured that the containerhead is locked in place.

A pressure switch 164 is disposed in series between line 154 and theparallel combination of lamps 88 and 88' connected in parallel betweenswitch 164 and line 152. Switch 164 is illustrated in FIG. 9 and is aswitch indicating the pressure in unlock line 166 which operatescylindcrs 102 to an unlocked position. During unlocking, all thecylinders 102 must be returned to an unlocked position before sufficientpressure builds up in line 166 for operating switch 164. Returning toFIG. 8, an operators switch 168 in the crane operators cab is connectedin series with near side arm solenoid 170 between lines 152 and 154,while an operator's switch 172 also in the operators cab is disposed inseries with far side solenoid 174 between lines 152 and 154. Near sidesolenoid 170 operates hydraulic valve 176 in FIG. 9 for providinghydraulic fluid to a trio of cylinders 146 associated with guide 74 onone side and one end of the container head. Similarly, solenoid 174operates hydraulic valve 178 in FIG. 9 lowering the arms 124 associatedwith the remaining three guides 74 on the container head. Each of thevalves 176 and 178 is of the automatic return variety whereby when therespective switches 168 and 172 are opened, the corresponding arms 124will upraisc by reversing the flow of hydraulic fluid to the respectivecylinders 146.

Returning again to FIG. 8, lamp 86' and corners down lamp 86 areconveniently amber colored lights, locked" lamps 90 and 90' areconveniently green colored lights, and unlocked" lamp 88 and lamp 88 areconveniently red colored lights. Then, at the beginning of ordinaryoperation, the container head will be unlocked and free of a containerwhereby the red lights will be illuminated. The operator may guide thecontainer head into the proper position through manipulation of thecrane and the tag motor clutches, with an appropriate one of switches168 and 172 closed to lower guide arms on the side and end of thecontainer head farthest from the container. When the container head isguided into place and fully lowered onto a container, and all fourcorners are in place but not locked. the amber lamps 86 and 86 willlight indicating to the operator that he may lock the container head inplace. Switch may be thrown from the right-hand position to theleft-hand position causing the locks to operate, turning on green lamps90 and 90' and turning off red lamps 88 and 88'. Now the load may beraised with the crane causing the amber lamps 86 and 86' to go out asthe weight of the container is borne by the container head rather thanvice versa. The corner locks cannot be unlocked at this time. When theload is deposited in place and fully supported from underneath, theamber lights 86 and 86' become illuminated and the switch 160 can beeffectively thrown from the left-hand position to the right-handposition causing unlocking of the corners of the container head. At thistime, the red lamps 88 and 88 are illuminated once again and green lamps90 and 90' go out.

The above procedure is particularly advantageous when the crane operatoris depositing cargo containers in the hold of a ship where the actualsituation of the container cannot be observed by sight. The lamps 86',88' and 90' on the container head itself will also warn longshoremen,ships crew, etc., of the intended operation of the device. The overallsystem has been found highly advantageous in the expeditious and safeloading and unloading of container cargoes.

While we have shown and described a preferred embodiment of ourinvention, it will be apparent to those skilled in the art that manychanges and modifications may be made without departing from theinvention in its broader aspects. We therefore intend the appendedclaims to cover all such changes and modifications as fall within thetrue spirit and scope of our invention.

We claimi 1. A crane system for moving a cargo container, said systemcomprising:

a crane having a crane boom and a crane operator's cab,

a container head adapted to be received upon the top of said container,said container head having four remotely operated locking memberslocated substantially at corners of said container head for engagingmating locking devices provided at the top of a container,

cable means for suspending said container head and container lockedthereto from said crane boom,

21 first group of four switching devices located on the container headand responsive to the containers presence for preventing unlocking ofsaid locking members when said container head is not resting on saidcontainer,

four additional switching devices located on the container head andresponsive to operation of said locking members,

and indicating means located in the operators cab and electricallycoupled to said container head for indicating to the crane operator theposition of said first group of four switching devices and the positionof said four additional switching devices,

whereby, when the crane lifts the container, said container head is notresting on said container and upon lowering of the container onto asupporting surface said container head rests on the container and saidindicating means thereby provides an indication to an operator in saidoperators cab that the container is fully down on the said supportingsurface.

2. The system according to claim 1 wherein said first group of fourswitching devices comprise pressuresensitive switching devices locatedsubstantially at corners of said container head and operative when theweight of said container head is not resting on said container forinhibiting unlocking operations of said locking members.

3. The system according to claim 2 wherein said first group of switchingdevices are each provided with an actuator movable upwardly anddownwardly according to whether the weight of said container head restson said container or said container head carries said container as thesame is upraised by said cable means.

4. The system according to claim 3 wherein said first 5 group of fourswitching devices have normally open contacts connected in series in aninterlocking circuit for providing power to said locking members, eachof said first group of switching devices being operable from a normallyopen to a closed condition as the actuator therefor indicates saidcontainer head is resting on said container.

5. The system according to claim 4 also including indicating means onsaid container head for indicating the position of said switchingdevices and the position of said locking members.

6. The system according to claim 1 wherein said cable means comprises apair of cables extending from a crane boom adapted to be raised andlowered from a pair of drums,

a spreader bar suspended at respective ends thereof by said pair ofcables for positioning said cables apart, including means for connectingsaid spreader bar to said pair of cables,

and further pairs of cables extending from each end of said spreader barto corners of said container head wherein the last mentioned pairs ofcables make an angle of nearly l80 with the first mentioned pair ofcables for carrying said container head and container with a minimum ofcontainer head weight-carrying structure.

7. The system according to claim 1 further including a plurality ofhingeable guides located on said container head and adapted to berotated into a position extending downwardly from said container headfor contacting sides of said container when said container head is movedinto place, upon said container,

said guides each comprising a first arm pivotally con nected to saidcontainer head and operating means for rotating said arm from anupraised position to a downwardly extending position for juxtapositionwith a side of a container,

and hook means on the side of said container head for receiving aportion of each said arm for bracing each said arm in said downwardlyextending position relative to thrust of horizontal forces against saidarm as said arm encounters the side of a container.

8. The system according to claim 7 including means for remotelyoperating said guides in groups.

9. A crane system for moving a cargo container, said system comprising:

a crane having a crane boom and a crane operators cab,

a container head adapted to be received upon the top of said container,said container head having four remotely operated locking memberslocated substantially at corners of said container head for engagingmating locking devices provided at the top of a container,

cable means for suspending said container head and container lockedthereto from said crane boom,

four switching devices located on the container head and responsive tothe conntainers presence for preventing unlocking of said lockingmembers when said container is present,

indicating means located in the operator's cab and electrically coupledto said container head for indicating to the crane operator the positionof said switching devices and the position of said locking members,

a plurality of hingeable guides located on said container head andadapted to be rotated into a position extending downwardly from saidcontainer head for contacting sides of said container when saidcontainer head is moved into place, upon said container,

said guides each comprising a first arm pivotally con- 1 nected to saidcontainer head and operating means for rotating said arm from anupraised position to a downwardly extending position for juxtapositionwith a side of said container,

a linkage for rotating said arm, said linkage comprising second andthird arms pivotally connected to the first mentioned arm and saidcontainer head respectively and pivotally connected to one another, saidoperating means comprising a hydraulic cylinder for rotating the thirdarm pivotally connected to said container head,

and means on the side of said container head for bracing each said firstmentioned arm in said downwardly extending position relative to thrustof lateral forces against said arm as said arm encounters the side of acontainer.

10. The system according to claim 9 wherein said means for bracingcomprises a hook-shaped member on the side of said container head havingan upwardly facing opening for receiving the pivotal connection betweentirst and second arms as the first arm rotates downwardly, the side ofsaid hook-shaped member resisting lateral force against said first armas said first arm encounters the side of said container.

11. A crane system for moving a cargo container,

said system comprising:

a crane having a crane boom and a crane operator's cab,

a container head adapted to be received upon the top of said container,said container head having four remotely operated locking memberslocated substantially at corners of said container head for engagingmating loclting devices provided at the top of a container,

cable means for suspending said container head and container lockedthereto from said crane boom,

four switching devices located on the container head and responsive tothe container's presence for preventing unlocking of said lockingmembers when said container is present,

indicating means located in the operators cab and electrically coupledto said container head for indicating to the crane operator the positionof said switching devices and the position of said locking members,

a pair of clutch-operated tag motors mounted on the crane which suspendssaid cable means,

said tag motors being separately operable and each including a reel anda tag cable drawn around a said reel,

and sheave means mounted on the boom of said crane at an intermediatelocation along the length thereof,

the cable from the tag motor reels passing over said sheave means toseparate locations on the side of said container head.

1. A crane system for moving a cargo container, said system comprising: a crane having a crane boom and a crane operator''s cab, a container head adapted to be received upon the top of said container, said container head having four remotely operated locking members located substantially at corners of said container head for engaging mating locking devices provided at the top of a container, cable means for suspending said container head and container locked thereto from said crane boom, a first group of four switching devices located on the container head and responsive to the container''s presence for preventing unlocking of said locking members when said container head is not resting on said container, four additional switching devices located on the container head and responsive to operation of said locking members, and indicating means located in the operator''s cab and electrically coupled to said container head for indicating to the crane operator the position of said first group of four switching devices and the position of said four additional switching devices, whereby, when the crane lifts the container, said container head is not resting on said container and upon lowering of the container onto a supporting surface said container head rests on the container and said indicating means thereby provides an indication to an operator in said operator''s cab that the container is fully down on the said supporting surface.
 2. The system according to claim 1 wherein said first group of four switching devices comprise pressure-sensitive switching devices located substantially at corners of said container head and operative when the weight of said container head is not resting on said container for inhibiting unlocking operations of said locking members.
 3. The system according to claim 2 wherein said first group of switching devices are each provided with an actuator movable upwardly and downwardly according to whether the weight of said container head rests on said container or said container head carries said container as the same is upraised by said cable means.
 4. The system according to claim 3 wherein said first group of four switching devices have normally open contacts connected in series in an interlocking circuit for providing power to said locking members, each of said first group of switching devices being operable from a normally open to a closed condition as the actuator therefor indicates said container head is resting on said container.
 5. The system according to claim 4 also including indicating means on said container head for indicating the position of said switching devices and the position of said locking members.
 6. The system according to claim 1 wherein said cable means comprises a pair of cables extending from a crane boom adapted to be raised and lowered from a pair of drums, a spreader bar suspended at respective ends thereof by said pair of cables for positioning said cables apart, including means for connecting said spreader bar to said pair of cables, and further pairs of cables extending from each end of said spreader bar to corners of said container head wherein the last mentioned pairs of cables make an angle of nearly 180* with the first mentioned pair of cables for carrying said container head and container with a minimum of container head weight-carrying structure.
 7. The system according to claim 1 further including a plurality of hingeable guides located on said container head and adapted to be rotated into a position extending downwardly from said container head for contacting sides of said container when said container head is moved into place, upon said container, said guides each comprising a first arm pivotally connected to said container head and operating means for rotating said arm from an upraised position to a downwardly extending position for juxtaposition with a side of a container, and hook means on the side of said container head for receiving a portion of each said arm for bracing each said arm in said downwardly extending position relative to thrust of horizontal forces against said arm as said arm encounters the side of a container.
 8. The system according to claim 7 including means for remotely operating said guides in groups.
 9. A crane system for moving a cargo container, said system comprising: a crane having a crane boom and a crane operator''s cab, a container head adapted to be received upon the top of said container, said container head having four remotely operated locking members located substantially at corners of said container head for engaging mating locking devices provided at the top of a container, cable means for suspending said container head and container locked thereto from said crane boom, four switching devices located on the container head and responsive to the conntainer''s presence for preventing unlocking of said locking members when said container is present, indicating means located in the operator''s cab and electrically coupled to said container head for indicating to the crane operator the position of said switching devices and the position of said locking members, a plurality of hingeable guides located on said container head and adapted to be rotated into a posiTion extending downwardly from said container head for contacting sides of said container when said container head is moved into place, upon said container, said guides each comprising a first arm pivotally connected to said container head and operating means for rotating said arm from an upraised position to a downwardly extending position for juxtaposition with a side of said container, a linkage for rotating said arm, said linkage comprising second and third arms pivotally connected to the first mentioned arm and said container head respectively and pivotally connected to one another, said operating means comprising a hydraulic cylinder for rotating the third arm pivotally connected to said container head, and means on the side of said container head for bracing each said first mentioned arm in said downwardly extending position relative to thrust of lateral forces against said arm as said arm encounters the side of a container.
 10. The system according to claim 9 wherein said means for bracing comprises a hook-shaped member on the side of said container head having an upwardly facing opening for receiving the pivotal connection between first and second arms as the first arm rotates downwardly, the side of said hook-shaped member resisting lateral force against said first arm as said first arm encounters the side of said container.
 11. A crane system for moving a cargo container, said system comprising: a crane having a crane boom and a crane operator''s cab, a container head adapted to be received upon the top of said container, said container head having four remotely operated locking members located substantially at corners of said container head for engaging mating locking devices provided at the top of a container, cable means for suspending said container head and container locked thereto from said crane boom, four switching devices located on the container head and responsive to the container''s presence for preventing unlocking of said locking members when said container is present, indicating means located in the operator''s cab and electrically coupled to said container head for indicating to the crane operator the position of said switching devices and the position of said locking members, a pair of clutch-operated tag motors mounted on the crane which suspends said cable means, said tag motors being separately operable and each including a reel and a tag cable drawn around a said reel, and sheave means mounted on the boom of said crane at an intermediate location along the length thereof, the cable from the tag motor reels passing over said sheave means to separate locations on the side of said container head. 